<template>
  <div>
    <span >全选:</span>
    <input type="checkbox" v-model="full"/>
    <button @click="fn">反选</button>
    <ul >
      <li v-for="item in arr" :key="item.name">
        <input type="checkbox" v-model="item.c"  />
        <span>{{item.name}}</span>
      </li>
    </ul>
  </div>
</template>

<script>
export default {
  data() {
    return {
      arr: [
        {
          name: "猪八戒",
          c: false,
        },
        {
          name: "孙悟空",
          c: false,
        },
        {
          name: "唐僧",
          c: true,
        },
        {
          name: "白龙马",
          c: false,
        },
      ],
    };
  },
  methods:{
    fn(){
      this.arr.forEach(item=>(item.c =!item.c))
    }
  },
  computed:{
    full:{
      get(){
        return this.arr.every(item=>item.c)
      },
      //在计算属性被修改时候调用
      //value 就是计算属性即将被改变的值
      set(a){
        this.arr.forEach(item=>item.c = a)
        
      }
    }
  }
};
</script>

<style>
</style>